Sorry for the delay – I somehow missed the notification about this question.
Not 100% sure because you don’t give me much details on how it is not working, but my guess is that you have installed DFFS with an earlier version of the DFFS installer that did not use a relative link to the form (this was updated November 25, 2020). The change in this version is only relevant in case you change the URL of the portal like you have done, or you save a site as a template.
Try uninstalling and reinstalling DFFS in the forms using the DFFS installer (you don’t need to update to the latest version if you already use DFFS installer v2). The config for your form is not affected by uninstalling and reinstalling – it will pop back when you reinstall.
If this don’t work you must give me some more details on what kind of error message you get.